Surgical staplers typically employ an anvil having staple pockets defined therein. Staples are pushed out of a staple cartridge through a section of tissue and against the staple pockets, the staple pockets being shaped so as to receive and progressively bend the legs of the staple into a closed position. FIG. 1 is a top view of a portion of conventional staple pocket arrangements on the anvil of a surgical stapler, e.g., a first arrangement on the upper side of the knife slot and a second arrangement on the lower side of the knife slot. Conventional staple pockets are typically rectangular in shape and maybe arranged in parallel rows.
FIG. 2(a) is a bottom perspective view of a conventional staple pocket arrangement on the anvil of a surgical stapler. This staple pocket arrangement employs a steep canyon wall near the floor of the canyon which changes to a shallow angle for the rest of the canyon wall. FIG. 2(b) is a cross-sectional view of a portion of the staple pocket illustrated in FIG. 2(a). FIG. 2(b) illustrates the staple leg being received within the staple pocket, e.g., moving in a vertical direction, and prior to the staple leg being bent into a closed position. The angle of 25.4 degrees shown in FIGS. 2(a) and 2(b) is the angle of the surface of the staple pocket relative to the plane of the anvil surface, e.g., the slope angle of the surface along which the staple leg slides when the staple leg is initially received within the staple pocket at a location about 0.005 inches from the longitudinal edge of the staple pocket.
FIG. 3(a) is a bottom perspective view of another conventional staple pocket arrangement on the anvil of a surgical stapler. This staple pocket arrangement employs a steep canyon wall near the floor of the canyon which changes to a shallow angle for the rest of the canyon wall. FIG. 3(b) is a cross-sectional view of a portion of the staple pocket illustrated in FIG. 3(a). FIG. 3(b) illustrates the staple leg being received within the staple pocket, e.g., moving in a vertical direction, and prior to the staple leg being bent into a closed position. The angle of 37.4 degrees shown in FIGS. 3(a) and 3(b) is the angle of the surface of the staple pocket relative to the plane of the anvil surface, e.g., the slope angle of the surface along which the staple leg slides when the staple leg is initially received within the staple pocket at a location about 0.005 inches from the longitudinal edge of the staple pocket.
FIG. 4 is a top view of a portion of another conventional staple pocket arrangement on the anvil of a surgical stapler. In this arrangement, there are three longitudinal rows of the staple pockets located on each side of the knife slot.
One problem that may be encountered by conventional surgical staple pocket arrangements is that the staple pockets have sharp internal corners that may contribute to snagging or stalling the staple leg of a staple as the staple leg is progressively moved through the staple pocket. Another problem that may be encountered by conventional surgical staple pocket arrangements is that the staple pockets have a narrow capture area, such that staples that are slightly mis-aligned relative to the staple pockets may miss the pocket. Another problem that may be encountered by conventional surgical staple pocket arrangements is that the staple pockets may have too shallow a slope spread over a broad area so that incoming staple legs do not encounter a sufficiently steep slide angle, thereby causing the staple legs to stall and buckle.